Phonograph sound-box



A. A. DENNIS.

.PHONOGRAPH SOUND BOX.

APPLICATION HLED JUNE 21.1920.

1,393,434? Patented Oct. 11,1921.

n A A s u rso s'rTEs ALFRED A. DENNIS, F snafu-'1) RAPIDS, MICHIGAN."

PHONOGRAPH SOUND-BOX.

ieeaaaa.

To. all whom it may concern:

Be it kIWI1l1l1&l)I., ALFRED A. DENNIS, a citizen of the United States of America, residing ,atGrand Rapids, in the county of Kent and State of Michigan, have invented certain new and useful Improvements in Phonograph Sound-Boxes; and I do hereby declare the following to be a full, clear, and

exact description of the invention, such as 1: ing ofi' sound waves which are carried to and amplified in any suitable amplifying horn or the like. It is an object and purpose of mylnvention to associate a means in connection wlth sald vlbratlng diaphragm .which will serve to, in a measure, modify the action of the same and change the character of the sound waves given off, resulting in better tone with an elimination of mechanical soundsand twangs which are usually present, a softer-yet fuller tone being produced, A further object of the invention is .to provide means for. diii'erently influencing the action of the diaphragm, so that the same may be changed for the reproduction of instrumental selections alone and likewisefor the reproduction of vocal and instrumental combined. This is desirable as vocal reproduction is quite difierent from instrumental reproduction on phonographs. A further object of the invention isto make a sound box or .reproducer having the improvements stated at a very low additional cost over sound boxes not so equipped.

Many other objects and purposes will appear fully and in detail as understanding of the invention is had from the following description, taken in connection with the accompan 'ng drawing, in which,

lhgure 1 is a plan view of a sound box or reproducer equipped with my invention, and

Fig. 2 is a central vertical section therethrough.

Like reference characters refer to like parts in the different figures of the drawing. The sound box casing 1 is of the usual construction and is attached atthe end of the tone arm 2. A thin diaphragm 3 is permanently secured in the casing 1, any suit- Spe eification of Letters Patent. Application filed June 21,

"Patented Uct. ii, 19211..

1920. Serial No. 390,352.

able means of securing the same being used.

A relatively heavy coiled spring 4 is con; nected atone end to the center of the diaphragm by means of a screw 5 which also may serve toattach the stylus 6-to tl1e"diaphragm, said stylus being equipped with the usual needle holder 7 in which the needle for traversing the records is held.

Sprlng 4i extends into the tone arm for a dlstance. A. bar 8 having a .downturned end 8 is'mounted within and at the upper side i of thetone arm, its downturned end carryinga head 9 which is adapted to engagewith the free end of spring i whenmoved to one position. To mount the bar 8 a short rod 10 is attached thereto and passed through a slot 11 in the upper side of the tone arm 2, belng equipped with an operating knob or handle 12 at its upper endand carrying a friction leaf spring 13 disposed between the handle 12 and a plate 1 1 fastenedto the upper side of the tone arm and likewise slotted for the passage of rod 10. A pointer- 15 is made integral with the spring 13 and is used to indicate the positions to which the device should be moved, plate 14 carrying two indicating characters, one, I and the other V I, indicating instrumental and the combination of vocal and instrumental. lVhen the pointer points to the character I, head 9 is freeot' the end of spring 4, but when the pointer points to the characters VI, said head bears against the free end of the spring and compresses it to a slight degree. The end of the slot toward the sound box limits the extent of movement of the head 9 which can not be too much as too great pressure against the spring transmittedtothe diaphragm will substantially check vibration and mute the tones.

When the spring hangs free on the dia- ,phragm,the weight thereof serves to modify is very markedly benefited. For vocal pieces and those accompanied by instruments, said instrumental parts being subordinate to the vocal, the head 9 should be moved into contact with the spring and compress it slightly.

-orless against the spring, the leaf spring 13 holding the device at any place to which it is moved, though too great pressure on the spring 4 c'annot'be made as the rod 10 is limited in movement by the end of the slot 11. The invention'has received practical test and proven its value, irrespective of whether or not the theory advanced above may be true and exact. I

The invention is capable of embodiment in various forms of construction, and I, accord ingly, do not wish to be limited to the exact structure shown and described, but consider myself entitled to'all forms of construction coming within the scope of the appended claims defining the invention.

I claim:

1. Ina phonograph sound box or reproducer, a casing, a diaphragm mounted in the casing, and a relatively heavy wire coil attached to the rear side of the diaphragm and extending therefrom, substantially as described.

' 2. In a phonograph sound box or reproducer, a casing, a'diaphragm mounted on the casing, a relatively heavy spring coil attached to the rear side of the diaphragm and extending therefrom, and means adjustably mounted to engage with the free end of the springer move away therefrom to leave said end of the spring free, substantially as described.

of the diaphragm, means adjustably mounted. at the free end of the spring and operable into and out of engagement with the same, and means for operating means manually, substantlally as described.

4. In a sound box or reprodncer, a reproducer casing and diaphragm therein, a tone arm on the end of which the casing is mounted, a relatively heavy coiled spring attached to the rear side of the diaphragm and extending into the tone arm, and means adjustably mounted on the tone arm adjacent the free end of the spring and operable into and out of engagement therewith, said means when engaged with the spring slightly compressing the same, substantially as described.

In a phonograph sound box or reproducer, the combination of the reproduccr casing and diaphragm therein, of a relatively heavy coiled spring attached to the rear side of the diaphragm, a tone arm to the end of which the casing is attached and into which the spring extends, means adjustably mounted on the tone arm adjacent the free end of the spring and operable into and out of engagement therewith, and means attached to said adjustable means and manually operable from outside the tone arm tor moving said adjustable means into and out ofengagement with the spring, substantially as described.

6. In a phonograph sound box or reproducer, the combination of the reprodurer casing and diaphragm therein, of a relatively heavy coiled spring attached to the rear side of the diaphragm, a tone arm to the end of which the casing is attached and into which the spring extends, a bar mounted within the tonearm and provided with a head disposed adjacent the free end of the spring, means for slidably mounting said bar on the arm to bring the head into engagement with the free end or the spring or to carry said head away from the spring, and means for operating said bar in its movements from without the tone arm, substantially as described.

'7. The combination of elements defined in claim 6 combined with yielding means for retaining the bar in any position to which it is moved, substantially as described.

8. The combination of elements defined in claim 5, combined with means for yieldingly holding the said adjustable means in positions to which it may be moved, substantially as described.

In testimony whereof I afiix my signature.

ALFRED A. DENNIS. 

